Final answer:
Function f(x) = 7x is continuous for all real numbers and has no discontinuities; thus, there is no x-value at which f is not continuous, and no discontinuity to be considered removable.
Step-by-step explanation:
The question asks to find the x-value at which the function f(x) = 7x is not continuous and to determine whether the discontinuity is removable. This function is a simple linear function which is continuous for all real numbers. There are no values of x for which this function becomes undefined or shows any sort of break. Therefore, the function f(x) = 7x is continuous across its entire domain, which includes all real numbers. Since there are no discontinuities, there is no need to discuss the concept of a removable discontinuity for this particular function.